Evaporator



Dec 21, 1937.

E. WITZEL EVAPORATOR Filed May 16, 1935 2 'Sheets$heet l In uemor Wit)193 MK attorney.

IE. WlT ZEL Dec. 21, 1937.

\ EVAiORATOR Filed May 16, 1935 2 Sheets-Sheet 2 11121621102 Wiv- 53@519 TTOI I" [1 31.

Patented Dec. 21, 1937 UNITED STATES EVAPORATOR Ernst Witael, Racine,

Radiator Company,

Application May 16,

6 Claims.

The object of the present invention is to economically distribute therefrigerant to the various coils in the evaporator.

In devices of the class, it is customary to dis- 5 charge the liquidrefrigerant by means of an expansion valve, into a common header havingindividual tube outlets which lead to the various individual coils ofthe evaporator. Frequently the header is made long enough to receive a;direct connection from the inlet end of each individual coil.

It has previously been diflicult to distribute the refrigerant equallyto each coil, partially because some of the refrigerant flashes intovapor immediatelyit enters the header.

A- mixture of vapor and liquid or liquid only, conceivably would bedimcult to distribute to large spaced apart outlets, for variousreasons. Applicant provides means whereby the refrigerant is dischargedfrom the expansion .valve into a small distributing chamber havingsuitably positioned, closely spaced, relatively small outlets. Therewill, therefore, be little or no expansion of the refrigerant whilepassing through. this chamber. I also provide means whereby there willbe suitable turbulence in the, chamber to further cause equal quantitiesof the liquid, and gas, if any, to pass into the various outlets.

One of the objects of this invention is to provide secondarydistributing heads, whereby the refrigerant first distributed isconducted to individual secondary heads, where it is again divided inthe same manner as in the first head. Thus when there is a large numberof evaporator coils, particularly if their inlets are at varyingdistances from the primary distributing head,

' expansion is largely avoided until the refrigerant in liquid formenters the inlet end of the coils.

To these and other useful ends, my invention resides in features ofconstruction and combination of parts or their equivalents, ashereinafter set forth and claimed and shown in the accompanying drawingsin which;

Figure l is a front sectional view of one form ure 3.

Figure 2 is a front view of a modification showing a primarydistributing head and secondary heads in section and a fraction of aconventional evaporator.

Figure 3 is a sectional view of the header shown in Figure 1, taken online 3 of Figure 1.

Figure 4 is a front elevation of an evaporator equipped with one form ofmy invention.

Figure 5 is a sectional view of my secondary of my distributing headtaken on line of Fig-- Wis., assignor to Youn Racine, Wis.

1935, Serial No.

header as shown in Figure 4, taken on line 5 of Figure 4.

As thus' illustrated in Figures 1- and 3, the header housing isdesignated by numeral Numeral H designates afraction of an expansion 5valve or a restricted connection from the receiving tank. This member isusually screw threaded into the header, as indicated, and a slightlyprojecting nozzle I2, is frequently supplied as indicated, the headerhaving a chamber l3 and a bottom seat l4 which is preferably formed inthe shape of an inverted cone. In this design, which is suitable for afour coil evaporator, four orifices l5 are drilled through the seat 14and closely positioned, preferably in a small circle around the apex ofthe cone. One orifice is provided for each coil in the evaporator.

Orifices I5 are as closely spaced as it is possible to drill, howeverthey diverge outwardly.

making it possible to intersect the openings provided for the outlettubes 22, 23, 24, and 25,-each of which leads to the inlet of one of thefour evaporator coils.

I provide a cap 26, for the outlet opening formed by chamber l3 on theinner end of which a cone shaped projection 21 is, preferably, provided.The apex of projection 21 extends in front of the nozzle l2, thus tobreak up the entering refrigerant, cause the necessary turbulence andreduce the area of chamber l3.

Clearly the header shown in Figures 1 and 3, may be designed toaccommodate any reasonable number of evaporator coils; however Iillustrate, in Figure 2, a modification wherein each orifice in theconical seat, may serve two evaporator coils by providing secondaryheaders as follows: The primary header 30 is, preferably, similar tothat shown in Figures 1 and 3, wherein the conical seat is provided withorifices 3| which are large enough to serve two or more evaporator coilsas indicated. Outlet tubes 32, 33, and 34 each leads to a secondaryheader 35 and each secondary header is provided with two orifices 36 and31, which intersect openings provided for tube outlets 38 and 39, eachof which is adapted to be connected to the inlet of an evaporator coil.Orifices 36 and 31 are preferably about the size of orifices IS inheader ll] of Figures 1 and 3 and orifices 3! are somewhat larger.

Thus it will be seen that a larger number of coils may be served by theheader in the design shown in Figure 2, than would be possible in thedesign shown in Figure 1, in addition to other tion with Figures 4 and5.

" have a concave shape or be made fiat.

In the design of the evaporator shown in Figure 4 the coils arepositioned horizontally. Thus some of the coil inlets may be aconsiderable distance from the primary header. Applicant endeavors firstto equally distribute the refrigerant into the outlet tubes 4 I, 42, and43, each of which leads to a secondary header 44, the primary header 40being similar to header 30 of Figure 2, except in the position of theoutlets.

Secondary header 44, is provided with a chamber 45, which also answersas a receptacle for tubes 4|, 42, and 43. A cone shaped seat 46, isprovided. Two orifices 48 and 49 are drilled into the seat as in theother headers, intersecting the outlet connections for tubes 50 and 5|.

.Tube 50, leads directly into one of the evapo rator coils and tube 5|is adapted to lead into the adjacent coil. Thus each coil of a pair ofcoils is served by an orifice in the secondary header and each secondaryheader is served by a suitable orifice in the primary header 4!) in amanner which will insure equal distribution to the various coils of theevaporator, regardless of their position or distance from the primaryheader.

Obviously applicant's primary header may be adapted to serve anyreasonable number of coils and when used to distribute refrigerant tothe coils through secondary headers the distribution therefrom will beequally uniform.

The cone 21 may, obviously, be dispensed with or differently shaped, andfurther the expansion valve may be placed in the position now occupiedby the cap 26. The cone shaped seat may For the present purpose it willnot be necessary to enumerate all of the minor modificationscontemplated by applicant because each header may be variously designedand used separately or combined on any sort of evaporator. For example,two or more primary headers may be adapted to serve certain coils ofan'evaporator or a single header may be made to serve two or moreindividual evaporators.

Clearly the size of the orifices in either header will depend upon thediameter and length of the evaporator coils. The diameter of the tubesleading from either header, particularly from the primary to thesecondary header, may be quite small thus to largely avoid expansion ofthe refrigerant in its passage from the expansion valve to the coils.The pressure in the high side of the system will also be a materialfactor in determining these sizes. Applicant's device may be used undercertain conditions whereby what is termed an expansion valve may besupplied with a non-restrictive outlet to the header whereby theorifices would in fact, be the expansion nozzles. In the design shown inFigure 2, orifices 36 and 31 could be made to act almost exclusively asexpansion outlets provided orifices 3| were made relatively large. p I

Having thus shown and described my invention I claim 1. Ida device ofthe class described, comprising an evaporator having a number of coils,a refrigerant distributing head having a chamber having a seat in itsbottom in the shape of an inverted cone, small outlet orifices closelyspacedaround the apex of said seat, each having 2. In a device of theclass described, comprising an evaporator having a number of coils, arefrigerant distributing head having a chamber and an inverted coneshaped seat in its bottom,

outlet orifices closely spaced around the apex -of said seat, eachhaving an outlet connection to the inlet end of one of said coils, aninlet to said chamber adapted to receive the refrigerant, whereby therefrigerant is metered into, said coils and permitted to expandthereafter.

' 3. In a device of the class described, comprising an evaporator havinga number of coils, a refrigerant distributing head having a relativelysmall chamber, closely spaced small outlet orifices in the bottom ofsaid chamber, each having an outlet connection to the inlet end of oneof said coils, an inlet in said chamber adapted to receive therefrigerant, a removable closure for said chamber having a projectionwhich extends into the direct path of the refrigerant after leaving saidinlet, whereby the refrigerant is caused to be agitated before reachingsaid orifices. I

4. An evaporator distributing head comprising, a relatively smallchamber having closely spaced orifices in the bottom thereof, eachhaving a connection to an outlet tube, a refrigerant inlet to saidchamber and a removable projection which lies in the direct path of theincoming refrigerant to thereby cause turbulence and an equaldistribution of refrigerant into said orifices.

5. An evaporator of the class described, comprising a number of coils, aprimary header having a chamber with an inverted cone shaped bottomwhich is provided with a number of spaced apart outlet orificespositioned around the apex thereof, each orifice having a connection toa secondary header chamber, each said secondary header chamber having aninverted cone shaped bottom which is provided with a number of spacedapart orifices positioned adjacent the apex thereof, each of said lastnamed orifices having a connection to one of said coils, a refrigerantinlet in said primary chamber whereby the refrigerant is equally meteredinto said secondary chambers and then equally metered from saidsecondary chambers to one of said coils.

6. In a device of the class described,'compris ing an evaporator havinga number of individual coils, the combination ofa primary header havinga chamber and an inlet for the reception of a refrigerant, a pluralityof closely spaced outlet orifices concentrically positioned in thebottom of said chamber, a number of secondary headers each having achamber being operatively connected to one of said primary headeroutlets, a number of closely spaced concentrically positioned outletorifices in the bottom of said secondary header chambers, each of saidsecondary outlet orifices having a connection to the inlet of one ofsaid coils, whereby the refrigerant is equally distributed into saidsecondary header chambers and then equally distributed to saidindividual coils.

ERNST WITZEL.

